When it comes to layoffs, buyouts and other types of workforce reductions, sometimes who's not in the news is more interesting than who is.

In the Bay Area, where layoffs are announced almost every day, a handful of the largest technology companies -- including Sun Microsystems and Apple Computer -- have been missing in action.

Despite the pressure for profits, some companies are reluctant to ax workers when things get ugly. The cost of layoffs -- severance pay, reduced morale among survivors and recruiting expenses when things turn around -- can sometimes outweigh the benefits.

Moreover, some companies see slumps as an opportunity, a time to get ahead. "It is historically true in any industry, the easiest time for a company to gain market share is during downturns," says analyst Doug van Dorsten of Thomas Weisel Partners.

Last week, Sun Microsystems reported its first quarterly loss in 12 years. Yet in its conference call with analysts, Sun disclosed no plans to reduce head count.

Many of Sun's analysts and investors don't seem to mind.

"Sun has a lot of technical advantages in their products. Their decision to continue to invest in both R&D and to a certain extent in sales, despite the downturn in business and despite the fact that many of their competitors are cutting back, could allow them to strengthen their competitive advantage," says David Bailey, an analyst with Gerard Klauer Mattison.

"As a shareholder, I'm more than happy to suffer through a couple periods of soft earnings if (Sun) can outperform competitors in the long run," says Peter Sorrentino, manager of the Legg Mason Balanced Trust.

At the end of its fiscal fourth quarter, ended June 30, Sun had 43,683 employees -- one more person than it had at the end of its third quarter but almost 7,000 more than it had a year ago, according to Sun's Web site.

Meanwhile, Sun's revenue per employee fell to $417,800 at the end of the fourth quarter from $441,200 at the end of the third quarter and $427,900 a year ago.

Sun could do a layoff, if only a symbolic one, but "that would be a simple way out -- easier than some of the other cost-cutting moves we've been through, " Sun spokeswoman Diane Carlini says.

Of course, the company could announce a big layoff tomorrow, but Sun gazers cite several reasons why it probably won't.

Although Sun's workforce grew nearly 40 percent during the past two years, Sorrentino says it didn't get as bloated as many companies.

Also, "they're at the really early stages of a significant product transition to new servers and workstations based on the new UltraSPARC III chip," says van Dorsten. Slashing staff now could jeopardize that transition.

Adds van Dorsten, "the company has an extremely strong balance sheet and therefore has the wherewithal to add new products and work really diligently to gain market share."

Analyst Bailey compared Sun to Dell, which makes low-cost PCs and has had large layoffs.

"Those two companies have dramatically different strategies," he says.

"Sun has continued to concentrate on having a very robust portfolio of products. That requires a great deal of R&D investment. Dell's success comes from their low-cost model. They continue to reduce their costs so they can remain the low-cost producer. That has allowed them to gain a great deal of market share despite the downturn in demand," he says.

Sun has adopted a performance-rating system for employees, and low-rated workers are given the option of shaping up or shipping out. But Carlini denied rumors that the rating system has led to "phantom layoffs."

Among the Bay Area's 15 largest technology companies, ranked by sales, only four have not announced workforce reductions this year -- Sun, Apple, Advanced Micro Devices and Agilent, which cut salaries 10 percent in lieu of layoffs.

AMD, however, has quietly reduced its head count through attrition by 400 people, or about 2.7 percent, according to spokesman John Greenagel. The chipmaker cut its travel budget by half and has asked employees to bring their lunches to meetings.

On top of mandatory vacations this summer, AMD will require workers to take five more vacation days -- paid or unpaid -- during the Thanksgiving and Christmas holidays.

Apple has maintained its workforce at about 11,000 throughout the year. In a meeting with analysts last week, Chief Executive Officer Steve Jobs said: "Almost every single competitor has been doing massive layoffs and retrenching and restructuring, but we're doing quite the opposite. We're not laying off boatloads of people. We're taking those talented people and saying that if we're going to get out of this, we're going to get out of it by innovating our way out of it."

Don Luskin, chief executive of MetaMarkets.com, says that during the boom, a lot of tech companies were advertising for employees in South Bay cinemas in slide shows before the movie. Now, he says, only two are advertising: Brocade Communications and Veritas, both midsize companies involved in data storage.

A spokeswoman for Brocade, which added 100 people during the past quarter and now has 1,000, says it continues to hire in key areas.

Veritas laid off about 5 percent of its staff earlier this year for performance reasons and when it merged several marketing staffs into one. But the company plans to increase its head count from 5,532 now to 6,200 by year- end.

EBay, another midsize company, also continues to hire. It laid off about 50 people who worked in the offline divisions of companies it bought. But the 2, 000-person company has 43 positions posted on its Web site, including software engineer, tax analyst and shipping manager.

YAHOOPS

Tuesday's column said Robertson Stephens was among the brokerage firms whose research is now available for purchase on Yahoo Finance.

Yahoo prominently featured Robertson on the home page of its new service, called Research Package, and had Robertson analyst reports posted on its site.

Turns out Yahoo didn't have permission to use Robertson research, and all mention of the company has disappeared.

Yahoo blamed the snafu on Thomson Financial, which provides the research. Thomson chalked it up to a "miscommunication."